a=int(input(""))
if a>=30:
    print("Yes")
elif a<30:
    print("No") a=int(input("")) a int(input("")) int input("") input "" if a>=30:
    print("Yes")
elif a<30:
    print("No") a>=30 a 30 print("Yes") print "Yes" elif a<30:
    print("No") a<30 a 30 print("No") print "No" a=int(input("")) int(input("")) a
a=int(input(""))
if a>=30:
    print("Yes")
elif a<30:
    print("No")